As planarization techniques for semiconductor devices in semiconductor manufacturing processes, CMP (chemical mechanical polishing) methods are used. The CMP methods include a method that performs polishing while supplying slurry in which abrasive grains are dispersed in liquid.
In order to make it easy to polish a film formed on a semiconductor device, slurry added with an oxidizing agent such as hydrogen peroxide (H2O2) is used.
The addition amount of the oxidizing agent, i.e., the concentration of the oxidizing agent in the slurry is required to be highly accurately adjusted corresponding to a polishing target, polishing condition, or the like. In recent years, in particular, metal wiring has been formed as ultrafine patterns in association with increases in density, integration, and function of a semiconductor device, and in order to more highly accurately polish metal wiring parts, it is necessary to more highly accurately adjust the concentration of the oxidizing agent added to the slurry.
Note that conventionally the concentration of an oxidizing agent added to slurry has been measured by analyzing the concentration of the oxidizing agent in accordance with near-infrared spectroscopy using an absorption spectrometer as disclosed in Patent Literature 1.